getting Caused by: org.hibernate.QueryException: cannot dereference scalar collection element: roles - spring-boot

Question

I have this class , and i'am trying to acess mobileNumbers and roles from the user table , but being lazy intialized i keep getting 'lazy intialization error.
I do not wan't to remove the LAZY fetch as complete access of the object is rarely required , but is required. So to overcome it first i tried to add #Transactional but going by this article https://codete.com/blog/5-common-spring-transactional-pitfalls/ it seems a bad approch in my case, i tried using join fetch but it keeps giving multiplebagfetchexception ,hence i tried to fetch them one at a time ( Element Collections i mean)
with this repository class
public interface UserRespository extends JpaRepository<UserDao, Long> {
Optional<UserDao> getByUserNameIgnoreCase(String userName);
// Optional<UserDao> findByUserNameIgnoreCase(String userName);
#Query(value = "select dao.roles.roles from UserDao dao inner join dao.roles r on dao.userName in elements(r.userName) and upper(dao.userName) = upper(?1)")
Object getByUserNameIgnoreCaseComplete2(String userName);
}
then i get his error
Caused by: org.hibernate.QueryException: cannot dereference scalar collection element: roles
at org.hibernate.persister.collection.ElementPropertyMapping.toType(ElementPropertyMapping.java:33) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.persister.collection.AbstractCollectionPersister.toType(AbstractCollectionPersister.java:1644) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.tree.FromElementType.getPropertyType(FromElementType.java:396) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.tree.FromElement.getPropertyType(FromElement.java:515) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.tree.DotNode.getDataType(DotNode.java:682) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.tree.DotNode.prepareLhs(DotNode.java:265) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.tree.DotNode.resolve(DotNode.java:205) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:114) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:109) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:104) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.tree.DotNode.resolveSelectExpression(DotNode.java:744) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.HqlSqlWalker.resolveSelectExpression(HqlSqlWalker.java:1057) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectExpr(HqlSqlBaseWalker.java:2295) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectExprList(HqlSqlBaseWalker.java:2232) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectClause(HqlSqlBaseWalker.java:1503) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:585) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:313) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:261) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:271) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:191) ~[hibernate-core-5.3.9.Final.jar:5.3.9.Final]
... 112 common frames omitted
I'm not sure why i keep getting this error.Is there any other way i can get the entire object??
Please help.
The actual class
#Entity
#Table(name = "users")
#Data
#NoArgsConstructor
public class UserDao implements Serializable {
#Id
#GeneratedValue
private long id;
#Column(name = "user_name", nullable = false, unique = true)
private String userName;
#Column(name = "password", nullable = false)
private String password;
#ElementCollection(targetClass = java.lang.String.class)
#CollectionTable(name = "mobile_numbers_List",joinColumns = #JoinColumn(name = "user_name",referencedColumnName = "user_name"))
#Column(name = "mobile_number")
private List<String> mobileNumbers;
#ElementCollection(targetClass = java.lang.String.class)
#CollectionTable(name = "roles_list",joinColumns = #JoinColumn(name = "user_name",referencedColumnName = "user_name"))
#Column(name = "roles")
private List<String> roles;
}

Answer 1

This seems like a similar question you previous question , and the answer to the previous one and this one is same.
your query is wrong here
#Query(value = "select dao.roles.roles from UserDao dao inner join dao.roles r on dao.userName in elements(r.userName) and upper(dao.userName) = upper(?1)")
Object getByUserNameIgnoreCaseComplete2(String userName);
it's trying to fetch dao.roles.roles which if does not even exist.
here are some changes you should try
change dao.roles.roles to r (as you already created an alias , let's use it)
remove dao.userName in elements(r.userName) it's not required, spring does this automatically without even specifying it.
change the return type to list , it's ElementCollection i.e Collection of elements
this is how your final query would look like
#Query(value = "select r from UserDao dao inner join dao.roles r on upper(dao.userName) = upper(?1)")
List<String> getByUserNameIgnoreCaseComplete2(String userName);

Answer 2

Why did u comment out findByUserNameIgnoreCase ? findBy Worked for me
Take a peek in this page

Answer 3

The Problem is the dao.roles.roles in your query. Change it to dao.roles.
dao.roles in your case is a List<String> and a String does not have a property roles.